Front derailleur and chain guide of bicycle derailleur

Abstract

A front derailleur comprises a base member, a chain guide, and a linkage structure. The base member includes a mounting hole. The mounting hole has a center axis. The linkage structure comprises a first link member and a second link member. The first link member is pivotally coupled to the base member about a first pivot axis. The second link member is pivotally coupled to the base member about a second pivot axis. The first link member is pivotally coupled to the chain guide about a third pivot axis. The second link member is pivotally coupled to the chain guide about a fourth pivot axis. At least three of the first pivot axis, the second pivot axis, the third pivot axis, and the fourth pivot axis are non-parallel to and non-perpendicular to the center axis of the mounting hole.

What is claimed is: 
     
       1. A front derailleur comprising:
 a base member including a mounting surface being configured to be contactable with one of a bicycle frame and a clamp configured to couple the base member to the bicycle frame in a mounting state where the base member is mounted to the bicycle frame, the base member including a mounting hole through which a mounting fastener is to extend in a mounting state where the base member is mounted to a bicycle frame with the mounting fastener, the mounting hole provided on the mounting surface and having a center axis; 
 a chain guide movable relative to the base member, the chain guide including a first guide member and a second guide member spaced apart from the first guide member in a lateral direction to form a chain receiving slot therebetween; and 
 a linkage structure configured to movably couple the chain guide to the base member, the linkage structure comprising:
 a first link member pivotally coupled to the base member about a first pivot axis; and 
 a second link member pivotally coupled to the base member about a second pivot axis, the first link member being pivotally coupled to the chain guide about a third pivot axis, the second link member being pivotally coupled to the chain guide about a fourth pivot axis, 
 
 at least three of the first pivot axis, the second pivot axis, the third pivot axis, and the fourth pivot axis being non-parallel to and non-perpendicular to the center axis of the mounting hole, the center axis being inclined with respect to the at least three of the first pivot axis, the second pivot axis, the third pivot axis, and the fourth pivot axis when viewed in the lateral direction that is perpendicular to the at least three of the first pivot axis, the second pivot axis, the third pivot axis, and the fourth pivot axis. 
 
     
     
       2. A front derailleur comprising:
 a base member including a mounting surface being configured to be contactable with one of a bicycle frame and a clamp configured to couple the base member to the bicycle frame in a mounting state where the base member is mounted to the bicycle frame, the base member including a mounting hole through which a mounting fastener is to extend in a mounting state where the base member is mounted to a bicycle frame with the mounting fastener, the mounting hole provided on the mounting surface and having a center axis; 
 a chain guide movable relative to the base member, the chain guide including a first guide member and a second guide member spaced apart from the first guide member in a lateral direction to form a chain receiving slot therebetween; and 
 a linkage structure pivotally coupled to the base member, the linkage structure comprising:
 a first link member pivotally coupled to the base member about a first pivot axis; and 
 a second link member pivotally coupled to the base member about a second pivot axis, 
 
 at least one of the first pivot axis and the second pivot axis being non-parallel to and non-perpendicular to the center axis of the mounting hole, the center axis being inclined with respect to the at least one of the first pivot axis and the second pivot axis when viewed in the lateral direction that is perpendicular to the at least one of the first pivot axis and the second pivot axis. 
 
     
     
       3. A front derailleur comprising:
 a base member including a mounting surface configured to be contactable with one of a bicycle frame and a clamp configured to couple the base member to the bicycle frame in a mounting state where the base member is mounted to the bicycle frame; 
 a chain guide movable relative to the base member, the chain guide including a first guide member and a second guide member spaced apart from the first guide member in a lateral direction to form a chain receiving slot therebetween; and 
 a linkage structure configured to movably couple the chain guide to the base member, the linkage structure comprising:
 a first link member pivotally coupled to the base member about a first pivot axis; and 
 a second link member pivotally coupled to the base member about a second pivot axis, the first link member being pivotally coupled to the chain guide about a third pivot axis, the second link member being pivotally coupled to the chain guide about a fourth pivot axis, 
 
 at least three of the first pivot axis, the second pivot axis, the third pivot axis, and the fourth pivot axis being non-parallel to and non-perpendicular to a reference plane defined on an outer profile of the mounting surface when viewed in the lateral direction that is perpendicular to the at least three of the first pivot axis, the second pivot axis, the third pivot axis, and the fourth pivot axis. 
 
     
     
       4. A front derailleur comprising:
 a base member including a mounting surface configured to be contactable with one of a bicycle frame and a clamp configured to couple the base member to the bicycle frame in a mounting state where the base member is mounted to the bicycle frame; 
 a chain guide movable relative to the base member, the chain guide including a first guide member and a second guide member spaced apart from the first guide member in a lateral direction to form a chain receiving slot therebetween; and 
 a linkage structure configured to movably couple the chain guide to the base member, the linkage structure comprising:
 a first link member pivotally coupled to the base member about a first pivot axis; and 
 a second link member pivotally coupled to the base member about a second pivot axis, 
 
 at least one of the first pivot axis and the second pivot axis being non-parallel to and non-perpendicular to a reference plane defined on an outer profile of the mounting surface when viewed in the lateral direction that is perpendicular to the at least one of the first pivot axis and the second pivot axis. 
 
     
     
       5. A front derailleur comprising:
 a base member including a mounting surface being configured to be contactable with one of a bicycle frame and a clamp configured to couple the base member to the bicycle frame in a mounting state where the base member is mounted to the bicycle frame, the base member including a mounting hole through which a mounting fastener is to extend in a mounting state where the base member is mounted to a bicycle frame with the mounting fastener, the mounting hole provided on the mounting surface and having a center axis; 
 a chain guide movable relative to the base member, the chain guide including a first guide member and a second guide member spaced apart from the first guide member in a lateral direction to form a chain receiving slot therebetween; and 
 a linkage structure configured to movably couple the chain guide to the base member, the linkage structure comprising:
 a first link member pivotally coupled to the base member about a first pivot axis; and 
 a second link member pivotally coupled to the base member about a second pivot axis, the first link member being pivotally coupled to the chain guide about a third pivot axis, the second link member being pivotally coupled to the chain guide about a fourth pivot axis, 
 
 the second pivot axis and the fourth pivot axis being non-parallel to and non-perpendicular to the center axis of the mounting hole, the center axis being inclined with respect to the second pivot axis and the fourth pivot axis when viewed in the lateral direction that is perpendicular to at least one of the second pivot axis and the fourth pivot axis. 
 
     
     
       6. A front derailleur comprising:
 a base member including a mounting surface configured to be contactable with one of a bicycle frame and a clamp configured to couple the base member to the bicycle frame in a mounting state where the base member is mounted to the bicycle frame; 
 a chain guide movable relative to the base member, the chain guide including a first guide member and a second guide member spaced apart from the first guide member in a lateral direction to form a chain receiving slot therebetween; and 
 a linkage structure configured to movably couple the chain guide to the base member, the linkage comprising:
 a first link member pivotally coupled to the base member about a first pivot axis; and 
 a second link member pivotally coupled to the base member about a second pivot axis, the first link member being pivotally coupled to the chain guide about a third pivot axis, the second link member being pivotally coupled to the chain guide about a fourth pivot axis, 
 
 the second pivot axis and the fourth pivot axis being non-parallel to and non-perpendicular to a reference plane defined on an outer profile of the mounting surface when viewed in the lateral direction that is perpendicular to the second pivot axis and the fourth pivot axis. 
 
     
     
       7. A front derailleur comprising:
 a base member including a mounting surface configured to be contactable with a clamp configured to couple the base member to a bicycle frame in a mounting state where the base member is mounted to the bicycle frame; 
 a chain guide movable relative to the base member; and 
 a linkage structure configured to movably couple the chain guide to the base member, the linkage structure comprising:
 a first link member pivotally coupled to the base member about a first pivot axis; and 
 a second link member pivotally coupled to the base member about a second pivot axis, the first link member being pivotally coupled to the chain guide about a third pivot axis, the second link member being pivotally coupled to the chain guide about a fourth pivot axis, 
 
 at least three of the first pivot axis, the second pivot axis, the third pivot axis, and the fourth pivot axis being non-parallel to and non-perpendicular to a reference direction perpendicular to a reference plane defined on the mounting surface. 
 
     
     
       8. A front derailleur comprising:
 a base member including a mounting surface configured to be contactable with a clamp configured to couple the base member to a bicycle frame in a mounting state where the base member is mounted to the bicycle frame; 
 a chain guide movable relative to the base member; and 
 a linkage structure configured to movably couple the chain guide to the base member, the linkage structure comprising:
 a first link member pivotally coupled to the base member about a first pivot axis; and 
 a second link member pivotally coupled to the base member about a second pivot axis, 
 
 at least one of the first pivot axis and the second pivot axis being non-parallel to and non-perpendicular to a reference direction perpendicular to a reference plane defined on the mounting surface. 
 
     
     
       9. A front derailleur comprising:
 a base member including a mounting surface configured to be contactable with a clamp configured to couple the base member to a bicycle frame in a mounting state where the base member is mounted to the bicycle frame; 
 a chain guide movable relative to the base member; and 
 a linkage structure configured to movably couple the chain guide to the base member, the linkage structure comprising:
 a first link member pivotally coupled to the base member about a first pivot axis; and 
 a second link member pivotally coupled to the base member about a second pivot axis, the first link member being pivotally coupled to the chain guide about a third pivot axis, the second link member being pivotally coupled to the chain guide about a fourth pivot axis, 
 
 the second pivot axis and the fourth pivot axis being non-parallel to and non-perpendicular to a reference direction perpendicular to a reference plane defined on the mounting surface. 
 
     
     
       10. A front derailleur comprising:
 a base member; 
 a chain guide movable relative to the base member from a lower-gear position to a higher-gear position to move a chain in an outward-shifting direction, the chain guide being movable relative to the base member from the higher-gear position to the lower-gear position to move the chain in an inward-shifting direction which is an opposite direction of the outward-shifting direction; 
 a linkage structure configured to movably couple the chain guide to the base member, the linkage structure comprising:
 an inner link member pivotally coupled to the base member about a first pivot axis; and 
 an outer link member pivotally coupled to the base member about a second pivot axis, the outer link member being spaced apart from the inner link member in the outward-shifting direction; and 
 
 a motor unit configured to move the chain guide relative to the base member, the motor unit including a housing, 
 at least one of the inner link member and the outer link member being contactable with one of the base member and an outer surface of the housing to define at least one of the lower-gear position and the higher-gear position. 
 
     
     
       11. The front derailleur according to  claim 10 , wherein
 the inner link member is contactable with one of the base member and the outer surface of the housing to define the higher-gear position. 
 
     
     
       12. The front derailleur according to  claim 11 , wherein
 one of the base member and the outer surface of the housing includes a higher-gear positioning surface contactable with the inner link member to define the higher-gear position. 
 
     
     
       13. The front derailleur according to  claim 12 , wherein
 the inner link member is pivotally coupled to the chain guide about a third pivot axis, 
 the outer link member is pivotally coupled to the chain guide about a fourth pivot axis, 
 a first reference line extends through the first pivot axis and the second pivot axis as viewed along the first pivot axis, 
 a second reference line extends through the second pivot axis and the fourth pivot axis as viewed along the first pivot axis, 
 a third reference line extends through the third pivot axis and the fourth pivot axis as viewed along the first pivot axis, 
 a fourth reference line extends through the first pivot axis and the third pivot axis as viewed along the first pivot axis, and 
 the higher-gear positioning surface is provided between the second reference line and the fourth reference line as viewed along the first pivot axis. 
 
     
     
       14. The front derailleur according to  claim 10 , wherein
 the outer link member is contactable with one of the base member and the outer surface of the housing to define the lower-gear position. 
 
     
     
       15. The front derailleur according to  claim 14 , wherein
 one of the base member and the outer surface of the housing includes a lower-gear positioning surface contactable with the outer link member to define the lower-gear position. 
 
     
     
       16. The front derailleur according to  claim 15 , wherein
 the inner link member is pivotally coupled to the chain guide about a third pivot axis, 
 the outer link member is pivotally coupled to the chain guide about a fourth pivot axis, 
 a first reference line extends through the first pivot axis and the second pivot axis as viewed along the first pivot axis, 
 a second reference line extends through the second pivot axis and the fourth pivot axis as viewed along the first pivot axis, 
 a third reference line extends through the third pivot axis and the fourth pivot axis as viewed along the first pivot axis, 
 a fourth reference line extends through the first pivot axis and the third pivot axis as viewed along the first pivot axis, and 
 the lower-gear positioning surface is provided between the first reference line and the third reference line as viewed along the first pivot axis. 
 
     
     
       17. A front derailleur comprising:
 a base member; 
 a chain guide movable relative to the base member from a lower-gear position to a higher-gear position to move a chain in an outward-shifting direction, the chain guide being movable relative to the base member from the higher-gear position to the lower-gear position to move the chain in an inward-shifting direction which is an opposite direction of the outward-shifting direction, the chain guide comprising:
 an inner guide member configured to guide the chain in the outward-shifting direction; and 
 an outer guide member configured to guide the chain in the inward-shifting direction, the outer guide member being spaced apart from the inner guide member in the outward-shifting direction; and 
 
 a linkage structure configured to movably couple the chain guide to the base member, 
 the inner guide member including:
 an inner guide plate including an opening having an inner periphery; and 
 a surrounding wall extending from the inner periphery of the opening in one of the outward-shifting direction and the inward-shifting direction, the surrounding wall being provided to at least partly surround the opening. 
 
 
     
     
       18. The front derailleur according to  claim 17 , wherein
 the inner guide plate has an inner guide surface configured to be contactable with the chain when the inner guide plate guides the chain in the outward-shifting direction, and 
 the surrounding wall is at least partly inclined relative to the inner guide surface. 
 
     
     
       19. The front derailleur according to  claim 17 , wherein
 the surrounding wall includes an annular end defining an additional opening, and 
 the additional opening is smaller than the opening of the inner guide plate. 
 
     
     
       20. The front derailleur according to  claim 17 , wherein
 the surrounding wall is integrally provided with the inner guide plate as a one-piece unitary member. 
 
     
     
       21. The front derailleur according to  claim 17 , wherein
 the surrounding wall is provided to the inner guide surface of the inner guide plate and configured to push the chain in an outward-shifting operation in which the chain moves in the outward-shifting direction.